Fix memory stomping bug in astman.

This memset complained in dev mod on my Ubuntu box. The memset is both
unnecessary and dangerous. At this point, m hasn't been initialized
yet, so the memset will write off to whatever address happens to be
on the stack at the time.
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Merged revisions 409077 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 409083 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/12@409087 65c4cc65-6c06-0410-ace0-fbb531ad65f3

utils/astman.c

@@ -737,7 +737,6 @@ static int manager_login(char *hostname)
 					show_message("Login Failed", get_header(m, "Message"));
 				}
 			} else {
-				memset(m, 0, sizeof(*m));
 				manager_action("Login", 
 					"Username: %s\r\n"
 					"Secret: %s\r\n",